A breathing mask with removable filter is known from U.S. Pat. No. 5,732,695. A rigid frame, which has spacers arranged in a spoke-like pattern and a ring extending circumferentially on the outside, which is connected to the spacers, is provided as the carrier for the filter material. The frame has a connection adapter, with which the filter can be connected to the breathing mask. Both sides of the frame are lined with filter material, through which the breathing air enters the interior space of the filter, which interior space is formed by the spacers.
Even though the rigid frame has the advantage that the filter can be easily grasped and can be connected to the mask, the supporting properties of the breathing mask are compromised by the rigid filter frame, because shocks on the filter act directly on the breathing mask and the latter may slip as a result on the face of the mask user. In addition, the prior-art filter requires precise filter blanks, because these must be connected sealingly to the frame in the area of both the filter port and of the circumferential ring. Thus, small deviations in dimension of the filter blanks may lead to leaks at the connection seams. To obtain acceptable resistances to breathing, the spokes of the frame must be dimensioned such that the filter blanks of the front and rear sides of the frame do not touch each other. A slight vacuum is generated in the interior space of the filter during breathing in and a contact may develop in case the distance between the filter blanks is too small, as a result of which the passage area of the filter is reduced.